According to the elasTc rebound hypothesis, most earthquakes are produced by the rapid release of energy stored in rock that has been subjected to great forces. When the strength of the rock is exceeded, it suddenly breaks, releasing some of its stored energy as seismic waves. AFershocks and Â±oreshocks Even a great earthquake like the 1906 San Francisco earthquake usually does not release all the elasTc energy stored in the rock along a fault.
Type rating. A type rating is a regulating agency's certification of an airplane pilot to fly a certain aircraft type that requires additional training beyond the scope of the initial license and aircraft class training. What aircraft require a type rating is decided by the local aviation authority.
The steady-state load torque you need for an application will seldom match the rating of the motor exactly. For this reason, NEMA gives its standard motors a service factor rating (usually 1.15 for drip proof motors). This is for infrequent overloads that may occur.